Mobile apparatus for applying non-skid surface to road plate

ABSTRACT

An apparatus for applying a non-skid surface to at least one side of a road plate comprises an enclosure generally surrounding a conveyor to support a road plate during movement through a first station and a second station of the apparatus. The first station includes a positionable sandblasting nozzle for use in cleaning a side of the road plate, and the second station includes a positionable wire arc spray nozzle for use in applying a spray of molten metal and/or metal alloy droplets to the cleaned side of the road plate. The droplets adhere to the road plate and provide a non-skid surface that provides for better traction between the tires of vehicles that move over the road plate. The apparatus is supported on a frame having a plurality of wheels and may be moved to a field site on public roadways and apply the non-skid surface to road plates at a location at or near construction and repair locations where the road plates are used.

STATEMENT OF RELATED APPLICATIONS

This application depends from and claims priority to U.S. Provisional Application No. 62/099,543 filed on Jan. 4, 2015.

BACKGROUND

1. Field of the Invention

The present invention relates to a mobile apparatus for use in applying a non-skid surface to a road plate of the kind used to cover open trenches in roadways to sustain use while permitting ready access to subterranean infrastructure buried underneath the roadway.

2. Background of the Related Art

Road plates are widely used in the road construction, maintenance and repair industry to temporarily cover open trenches in roadways to sustain vehicular traffic on the roadway during peak use hours while permitting ready access to the open trench during off-peak hours for the repair and/or installation of subterranean infrastructure such as, but not limited to, pipelines, sewers, electrical systems and the like.

Road plates are generally made of plate steel for its strength and resilience, and are designed to support continued use of a roadway by vehicular traffic where an open trench or ditch would otherwise preclude such usage. A road plate may range in size from eight feet in length and four feet in width to twenty feet in length and eight feet in width, and these road plates may weigh up to 7,000 pounds or more.

Steel plates are, by their nature, smooth along the sides. While a non-skid coating or surfacing can be applied, these are subject to wear, especially on a busy roadway. Reapplication of a non-skid surface generally requires that the road plate be loaded onto a truck using heavy equipment, transported to a facility and unloaded for application of the non-skid surface. The road plate is then reloaded and transported back to the roadway for further use.

BRIEF SUMMARY

One embodiment of the apparatus of the present invention comprises a mobile road plate cleaning and non-skid surface applicator having a chain conveyor to support a road plate as it is moved through a first station, in which a side of the road plate is cleaned, to a second station, in which a non-skid surface is applied to the cleaned side of the road plate using wire arc spray equipment.

A conveyor is provided to support and move the road plate from a loading ramp at a first end of the apparatus to the first station, from the first station to the second station, and from the second station to the discharge ramp at the second end of the apparatus. In one embodiment of the apparatus of the present invention, a chain conveyor is used, but it will be understood by those skilled in the mechanical arts that the conveyor may utilize belts, rollers and the like.

The road plate is cleaned in a first station using sandblasting equipment. A nozzle is used to direct a high velocity stream of air and sand or other abrasive particles onto the targeted surface of the road plate to remove corrosion, oxidation, oils and other contaminants that may impair full adhesion of the non-skid coating to be applied in the second station. The sand or abrasive particles are collected in a boot disposed underneath the first station so that the material can be filtered and recycled for repeated use. Recycling of sand or abrasive particles used in sandblasting is known in the art. In one embodiment of the apparatus of the present invention, a sandblasting nozzle can be aimed at the targeted side of the road plate and moved in a predetermined pattern, including both lateral movement, from side to side, and axial movement, from end to end. For example, the sandblasting nozzle can be moved in a lateral direction, then in an axial direction that is perpendicular to the lateral movement, then in a reversed lateral direction, then in an axial direction, then again in the lateral direction, and so on until the targeted surface of the road plate has been cleaned. This movement can be described as a repeated and interlaced “S” pattern relative to the targeted surface of the road plate.

In another embodiment of the apparatus of the present invention, a sandblasting nozzle may be simply reciprocated from side to side as the road plate is advanced incrementally underneath the reciprocating sandblasting nozzle. It will be understood that using the conveyor that supports and moves the road plate through the apparatus to provide the axial component of movement, in combination with the reciprocating movement of the sandblasting nozzle, can provide the same repeating and interlaced “S” pattern relative to the targeted surface of the road plate, but at a lower cost due to the elimination of the more complex mechanism for positioning the sandblasting nozzle.

It should be noted that the same two approaches described above for positioning the sandblasting nozzle can be used in the second station for positioning the wire arc spray head that directs the molten droplets of the wire material onto the cleaned side of the road plate.

Wire arc spray equipment is known in the prior art and described in U.S. Pat. No. 5,791,560 to Rogers, et al. A variety of conductive metal wire types can be used with a wire arc spray head, such as those available from Thermion, Inc. of Silverdale, Wash., USA and also of Poulsbo, Wash., USA.

Wire arc spray technology generally relies on the use of two elongate wires having an electrical potential between them to create an arc as they are engaged one with the other. The arc generates heat according to the potential between the wires. The heat generated by the arc melts the material of the wires. The molten wire material is sprayed from the arc zone where the two wires engage to direct and to distribute small droplets of the molten wire material onto a targeted surface. The droplets adhere to and quickly solidify on the targeted surface and provide a non-skid coating.

In one embodiment of the apparatus of the present invention, the wire used to generate the arc and to coat the targeted surface is a ceramic core wire with one or more of aluminum, zinc, aluminum alloy, zinc alloy that is described in more detail in U.S. Pat. No. 6,190,740 to Frank Rogers. Very hard particles such as oxides and/or carbides are included to provide desired properties. The resulting surface prepared using this wire exhibits superior wear resistance and corrosion resistance.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is an elevation view of an embodiment of an apparatus of the present invention illustrating the pivoting loading ramp at a first end of the apparatus and the pivoting discharge ramp at the second end of the apparatus.

FIG. 2 is a modified view of FIG. 1 showing the discharge ramp pivoted to the deployed position, a road plate loaded onto the loading ramp and a road plate ready for removal from the discharge ramp.

FIG. 3 is a sectional view of FIG. 2 showing the sandblasting nozzle positionable proximal to the top portion of the first station and the wire arc spray nozzle positionable near the top portion of the second station of the embodiment of the apparatus of FIGS. 2 and 3.

FIG. 4 is a sectional view of FIG. 2 showing the three-strand chain conveyor provided to move the road plate from the loading ramp through the first and second stations to the discharge ramp.

FIG. 5 is an end view of the three-strand chain conveyor and drive motor.

DETAILED DESCRIPTION

One embodiment of the present invention comprises a frame having an enclosure and a plurality of wheels, a partition within the enclosure dividing a first station from a second station, the partition having an aperture for movement of a road plate therethrough, a loading ramp pivotally coupled to a first end of the frame, a discharge ramp pivotally coupled to a second end of the frame, a conveyor supported on the frame for moving a road plate from the loading ramp through the first station, the aperture of the partition, and the second station to the discharge ramp, a motor coupled to drive the conveyor to move a road plate supported thereon, a sandblasting nozzle disposed in the first station proximal to a top portion of the apparatus, a wire arc spray nozzle disposed in the second station proximal to the top portion of the apparatus, a wire arc spray head coupled to the wire arc spray nozzle, a reservoir to receive a supply of abrasive particles, a first spool of wire to feed the wire arc spray head, a second spool of wire to feed the wire arc spray head, a current source coupled to at least one of the first spool of wire and the second spool of wire, a first pressurized air conduit coupled at a terminus to the sandblasting nozzle, and a second pressurized air conduit coupled at a terminus to the wire arc spray nozzle. In one embodiment of the apparatus of the present invention, the apparatus further comprises a sandblasting nozzle positioning arm to vary the position of the sandblasting nozzle within the first station, and a wire arc spray nozzle positioning arm to vary the position of the wire arc spray nozzle within the second station. In one embodiment of the apparatus of the present invention, the apparatus comprises a first motor to operate the sandblasting nozzle positioning arm, and a second motor to operate the wire arc spray nozzle positioning arm.

An embodiment of the apparatus of the present invention is illustrated in the drawings that are appended to this application. A description of that embodiment of the apparatus is provided below. It will be understood that this description is not to be limiting of the scope of the apparatus of the present invention.

FIG. 1 is an elevation view of an embodiment of an apparatus 10 of the present invention illustrating the pivoting loading ramp 20 at a first end 11 of the apparatus 10 and the pivoting discharge ramp 30 at the second end 19 of the apparatus 10. The loading ramp 20 is illustrated as being in the deployed position for receiving and supporting a road plate (not shown). The loading ramp 20 is illustrated as having been pivoted about a pivotal coupling 23 that allows the loading ramp 20 to be pivoted in the direction of arrow 24 from a stowed position (not shown) to the deployed position and supported in the deployed position by a support leg 22 that is pivotally coupled to the loading ramp 20 at a leg pivot 21. The discharge ramp 30 is illustrated as being in the stowed position for convenient transport of the apparatus 10. The discharge ramp 30 is illustrated as having a pivotal coupling 33 that allows the discharge ramp to be pivoted in the direction of arrow 34 from a stowed position (shown in FIG. 1) to a deployed position and supported in the deployed position by a support leg 32 that is pivotally coupled to the discharge ramp 30 at a leg pivot 31. The apparatus includes an enclosure 12 that supports the various components of the apparatus 10 and includes a first station 40 and a second station 60.

FIG. 2 is a slightly modified view of FIG. 1 showing the discharge ramp 30 pivoted to the deployed position, a road plate 80 loaded onto the loading ramp 20 and a road plate 81 ready for removal from the discharge ramp 30.

FIG. 3 is a sectional view of FIG. 2 showing a sandblasting nozzle 41 positionable proximal to the top portion 28 of the first station 40 and a wire arc spray nozzle 61 positionable near the top portion 29 of the second station 60 of the embodiment of the apparatus 10 of FIGS. 2 and 3. The sandblasting nozzle 41 is movably disposed on support member 42 in the first station 40 of the apparatus 10 for reciprocating movement between a first side 17 of the apparatus 10 and a second side 18 of the apparatus 10 and in the direction shown by the double headed arrow 43, and the wire arc spray nozzle 61 is movably disposed on support member 62 in the second station 60 of the apparatus 10 for reciprocating movement between a first side 17 of the apparatus 10 and a second side 18 of the apparatus 10 and in the direction shown by the double headed arrow 63. The first station 40 and the second station 60 are separated by a partition 50 having an aperture (not shown) through which the conveyor (not shown) and road plate 80 may pass. The loading ramp 20 and the discharge ramp 30 are shown as being coupled to the first end 11 and the second end 19, respectively, of the apparatus 10.

FIG. 4 is a sectional view of FIG. 2 showing the three-strand chain conveyor 88 provided proximal to a lower portion 29 of the apparatus 10 to move the road plate 80 (not shown) from the loading ramp 20 through the first station 40 and the second station 60 to the discharge ramp 30. The conveyor 88 includes a plurality of conveyor axles 90 in a generally parallel and spaced-apart configuration one relative to the others, each conveyor axle 90 having at least three gears 92 in identical positions on each axle 90 so as to ensure alignment of the gears 92. Three chains 99 are installed on each series of aligned gears 92 to provide the moving support on which road plates 80 (not shown in FIG. 4) can be moved through the apparatus 10. It will be understood that the conveyor 88 can be operated to move a road plate 80 from the loading ramp 20 to the discharge ramp 30 by coupling a drive motor 95 to a drive gear 96 disposed on at least one driven axle 98.

FIG. 5 is an end view of the three-strand chain conveyor 88 of FIG. 4 and a drive motor 95 coupled to rotate the drive gear 96 and driven axle 98 of the conveyor 88 in the direction indicated by arrow 97. Rotation of the driven axle 98 rotates all other axles 90 through the chains 99 that couple each axle 90 to the driven axle 98. A road plate 80 (not shown) supported on the conveyor 88 will move along the conveyor 88.

It will be understood that the combination of the reciprocating movement of the sandblasting nozzle 41 in the direction of the arrow 43 and the reciprocating movement of the wire arc spray nozzle 61 in the direction of the arrow 63 and the movement of the road plate 80 (not shown) on the conveyor 88 enables the sandblasting nozzle 41 and the wire arc spray nozzle 61 to clean and apply a non-skid surface to an entire side of a road plate moved by the conveyor 88. The sandblasting nozzle 41 and the wire arc spray nozzle 61 each reciprocate between the first side 17 and the second side 18 of the enclosure 12, and the conveyor 88 can be intermittently activated to move the road plate 80 a predetermined distance within the first station 40, during sandblasting, and within the second station 60, during application of the non-skid surface, between reciprocation of the sandblasting nozzle 41 and/or the wire arc spray nozzle 61. This approach can be used to ensure that the entire side of the road plate 80 is cleaned by the sandblasting nozzle 41 and/or conditioned by the wire arc spray nozzle 61.

In another embodiment of the apparatus of the present invention, the sandblasting nozzle 41 and the wire arc spray nozzle 61 are movable within a plane. That is, the sandblasting nozzle 41 and the wire arc spray nozzle 61 are movable both laterally between the first side 17 and the second side 18 of the enclosure 12 and, at the same time, they are movable longitudinally between the first end 11 and the second end 19 of the enclosure 12. It will be understood that this type of enhanced movement can be obtained using prior art positioning devices.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components and/or groups, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.

The corresponding structures, materials, acts, and equivalents of all means or steps plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but it is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. 

What is claimed is:
 1. An apparatus, comprising: a mobile frame having a plurality of wheels to engage a support surface and a hitch connectable to a truck for moving the apparatus; a loading conveyor coupled to the frame and having a first plurality of rolling elements for engaging a lower side of a road plate and for enabling movement of the road plate in a first direction; a cleaning station disposed adjacent to the loading conveyor and having a second plurality of rolling elements coupled to the frame for engaging the lower side of the road plate, for rollably receiving the road plate from the loading conveyor and for supporting the road plate within the cleaning station, the second plurality of rolling elements oriented for translation of the road plate in the first direction; a sandblasting nozzle oriented to direct a high velocity stream of abrasive particles onto an upper side of the road plate with the road plate in the cleaning station; a third plurality of rolling elements coupled to the frame and deployable from a retracted position, in which an uppermost portion of each of the third plurality of rolling elements is below an uppermost portion of the second plurality of rolling elements, to a deployed position, in which the uppermost portion of each of the third plurality of rolling elements is above the uppermost portion of the second plurality of rolling elements, the third plurality of rolling elements oriented for translation of the road plate in a second direction perpendicular to the first direction; an application station disposed adjacent to the cleaning station and having a fourth plurality of rolling elements coupled to the frame for engaging the lower side of the road plate, for rollably receiving the road plate from the cleaning station and for supporting the road plate within the application station, the fourth plurality of rolling elements oriented for translation of the road plate in the second direction; a wire arc spray head oriented to direct a spray of molten material onto the upper side of the road plate, the wire arc spray head including two consumable electrodes, each comprising a conductive wire fed independently into the spray head, and a gas nozzle oriented to blow a stream of gas towards a zone of contact between the two consumable wires to spray a large plurality of molten metal droplets onto the upper side of the road plate; a fifth plurality of rolling elements coupled to the frame and deployable from a retracted position, in which an uppermost portion of each of the fifth plurality of rolling elements is below an uppermost portion of the fourth plurality of rolling elements, to a deployed position, in which the uppermost portion of each of the fifth plurality of rolling elements is above the uppermost portion of the fourth plurality of rolling elements, the fifth plurality of rolling elements oriented for translation of the road plate in a third direction perpendicular to the second direction; and an unloading conveyor coupled to the frame and having a sixth plurality of rolling elements for engaging the lower side of a road plate and for enabling movement of the road plate in the third direction for rollably receiving the road plate from the application station.
 2. The apparatus of claim 1, wherein the loading conveyor is pivotally coupled to the frame.
 3. The apparatus of claim 1, wherein the unloading conveyor is pivotally coupled to the frame.
 4. The apparatus of claim 3, wherein the loading conveyor is pivotally coupled to the frame.
 5. The apparatus of claim 1, wherein the third plurality of rolling elements is pivotally deployable from the retracted position to the deployed position.
 6. The apparatus of claim 1, wherein the third plurality of rolling elements is deployable from the retracted position to the deployed position by activation of a fluid cylinder.
 7. The apparatus of claim 1, wherein the fifth plurality of rolling elements is pivotally deployable from the retracted position to the deployed position.
 8. The apparatus of claim 1, wherein the fifth plurality of rolling elements is pivotally deployable from the retracted position to the deployed position by activation of a fluid cylinder.
 9. The apparatus of claim 8, wherein the third plurality of rolling elements is pivotally deployable from the retracted position to the deployed position.
 10. The apparatus of claim 1, further comprising: an enclosure surrounding the cleaning station, the enclosure including a containment wall to contain abrasive particles.
 11. The apparatus of claim 1, further comprising: an enclosure surrounding the application station, the enclosure including a containment wall.
 12. The apparatus of claim 1, wherein the third direction is opposite to the first direction.
 13. The apparatus of claim 1, wherein the loading conveyor is connectable to and pivotable by a winch for moving the road plate from the loading conveyor to the cleaning station.
 14. The apparatus of claim 1, wherein the uppermost portion of each of the third plurality of rolling elements in the deployed position is above the uppermost portion of each of the fourth plurality of rolling elements of the application station.
 15. The apparatus of claim 1, wherein the uppermost portion of the fifth plurality of rolling elements in the deployed position is above the uppermost portion of each of the sixth plurality of rolling elements of the unloading conveyor.
 16. An apparatus, comprising: a frame having an enclosure and a plurality of wheels; a partition within the enclosure dividing a first station from a second station, the partition having an aperture for movement of a road plate therethrough; a loading ramp pivotally coupled to a first end of the frame; a discharge ramp pivotally coupled to a second end of the frame; a conveyor supported on the frame for moving a road plate from the loading ramp through the first station, the aperture of the partition, and the second station to the discharge ramp; a motor coupled to drive the conveyor to move a road plate supported thereon; a sandblasting nozzle disposed in the first station proximal to a top portion of the apparatus; a wire arc spray nozzle disposed in the second station proximal to the top portion of the apparatus; a wire arc spray head coupled to the wire arc spray nozzle; a reservoir to receive a supply of abrasive particles; a first spool of wire to feed the wire arc spray head; a second spool of wire to feed the wire arc spray head; a current source coupled to at least one of the first spool of wire and the second spool of wire; a first pressurized air conduit coupled at a terminus to the sandblasting nozzle; and a second pressurized air conduit coupled at a terminus to the wire arc spray nozzle.
 17. The apparatus of claim 16, further comprising: a sandblasting nozzle positioning arm to vary the position of the sandblasting nozzle within the first station; and a wire arc spray nozzle positioning arm to vary the position of the wire arc spray nozzle within the second station.
 18. The apparatus of claim 17, further comprising: a first motor to operate the sandblasting nozzle positioning arm; and a second motor to operate the wire arc spray nozzle positioning arm. 